Lifecycle CO₂ Reduction by Implementing Double Window Casement Systems in Residential Units in Korea

This study investigated lifecycle CO₂ (LCCO₂) emission reductions through application of double-window casement systems (DWCS) in residential units in Korea, compared with conventional single windows (SWs). The DWCS is a double window system that is energy-efficient, reducing energy consumption during operation. However, this system incorporates increased embodied CO₂ emissions. We evaluated LCCO₂ reductions associated with use of the DWCS by calculating CO₂ emissions during space conditioning as well as the embodied CO₂ emissions of the DWCS. The results showed that use of DWCS in a residential unit during the cooling season had 26.2 and 27.4 t CO₂ fewer emissions than SWs in the natural ventilation and minimum ventilation modes, respectively. Although implementation of DWCS is expected to substantially reduce LCCO₂ emissions, the large embodied CO₂ emissions of the aluminum frame reduce the benefits of the DWCS.